[Indole]naphthopyrans, preparation, compositions and (co)polymer matrices containing them, synthesis intermediates

ABSTRACT

The object of the present invention is novel photochromic [indole]naphthopyran compounds and their methods of preparation.

This application is a 371 of PCT/US98/21930 filed Oct. 20, 1998 whichclaims benefit of provisional application No. 60/070,381 filed Jan. 5,1998.

The present invention relates to novel [indole]naphthopyran compoundswhich have, in particular, photochromic properties. The invention alsorelates to:

compounds, synthesis intermediates, which are useful in the preparationof said [indole]naphthopyrans;

the preparation of said synthesis intermediates and said[indole]naphthopyrans;

photochromic compositions and photochromic ophthalmic articles (lensesfor example) which contain said [indole]naphthopyrans.

The photochromic compounds are capable of changing color under theinfluence of a poly- or mono-chromatic light (UV for example) and ofreturning to their initial color when the luminous irradiation ceases,or under the influence of temperature and/or a poly- or mono-chromaticlight different from the first.

The photochromic compounds find applications in various fields, e. g.for the manufacture of ophthalmic lenses, contact lenses, solarprotection glasses, filters, camera optics or photographic apparatusoptics or other optical devices and observation devices, glazing,decorative objects, bill elements or even for information storage byoptical inscription (coding).

In the field of ophthalmic optics, and in particular the spectaclestrade, a photochromic lens which comprises one or more photochromiccompounds must have:

a high transmission in the absence of ultraviolets,

a low transmission (high colorability) under solar irradiation,

adapted coloration and discoloration kinetics,

a tint acceptable to the consumer (gray or brown preferably) withpreferably a maintenance of the chosen tint during the coloration andthe discoloration of the lens,

a maintenance of the performances, the properties, within a temperaturerange of 0-40° C.,

a significant durability, since these objectives sought after aresophisticated corrective lenses and therefore expensive.

These lens characteristics are in fact determined by the activephotochromic compounds which they contain; compounds which mustfurthermore be perfectly compatible with the organic or inorganicsupport which constitutes the lens.

Moreover, it is to be noted that obtaining a gray or brown tint maynecessitate the use of at least two photochromes of different colors, i.e. having distinct maximal absorption wavelengths in the visible. Thisassociation further imposes other requirements of the photochromiccompounds. In particular, the coloration and discoloration kinetics ofthe (two or more) associated active photochromic compounds must beessentially identical. The same applies for their stability with timeand also for their compatibility with a plastic or inorganic support.

Amongst the numerous photochromic compounds described in the prior art,benzopyrans and naphthopyrans may be cited which are described inpatents or patent applications U.S. Pat. Nos. 3,567,605, 3,627,690,4,826,977, 5,200,116, 5,238,981, 5,411,679, 5,429,744, 5,451,344,5,458,814, WO-A-95 05382, FR-A- 2,718,447, WO-A-96 14596, WO-A-97 21698and in the Research Disclosure No. 36144, which are of the formulabelow:

These compounds claim to satisfy the specifications defined above. Inreality, if these compounds really do have one or more of the basicproperties sought after, such as a high transmission in the absence ofultraviolets and a high colorability under solar irradiation, none ofthe compounds described hitherto have the complete combination of theproperties sought after which are necessary for the production ofsatisfactory articles which may be manufactured industrially. Inparticular, none of these compounds is intrinsically gray or brown andthe necessity of using an additional photochrome in order to obtain oneof these two tints does subsist.

Several compounds having two intense and more or less complementaryabsorption bands in the visible have been described (WO-A-96 14596).These two bands are generally situated in the yellow/orange and in theviolet/blue. However, the first band (yellow) is far less intense andthe stability of these compounds vis-a-vis the photochromic ageing isfar from being satisfactory.

Although the general formula IA of the patent application WO-A-97 21698includes [indole]naphthopyrans, such [indole]naphthopyrans are notdescribed in this prior art document insofar as said document does notindicate any method of synthesizing said [indole]napthopyrans.[Indeno]naphthopyrans are effectively described in said document but nomeans of access to the [indole]naphthopyrans is suggested. It is to thecredit of the Applicant to have proposed such a means of access (anefficient synthesis method) and to have discovered that this type ofcompound possesses particularly advantageous photochromic properties.More specifically, they possess a particularly intense first band in theyellow/orange, a second band of high λ_(max) and a high colorability,even at 40° C., associated with rapid discoloration kinetics.

Thus, the object of the present invention is [indole]naphthopyrancompounds of formula (I):

in which:

R₁ and R₂, identical or different, independently represent:

hydrogen,

a linear or branched alkyl group having 1 to 12 carbon atoms,

a cycloalkyl group having 3 to 12 carbon atoms,

an aryl or heteroaryl group having 6 to 24 carbon atoms or 4 to 24carbon atoms respectively in its basic structure and at least oneheteroatom selected from sulfur, oxygen and nitrogen; said basicstructure optionally being substituted with at least one substituentselected from:

a halogen and notably fluorine, chlorine and bromine,

a linear or branched alkyl group having 1 to 12 carbon atoms,

a linear or branched alkoxy group having 1 to 12 carbon atoms,

a linear or branched haloalkyl or haloalkoxy group correspondingrespectively to the (C₁-C₁₂) alkyl and (C₁-C₁₂) alkoxy groups abovesubstituted with at least one halogen atom and notably a fluoroalkylgroup of this type,

a linear or branched alkenyl group having 2 to 12 carbon atoms andnotably a vinyl group or an allyl group,

an —NH₂ group,

an —NHR group, R representing a linear or branched alkyl group having 1to 6 carbon atoms,

 R′ and R″, identical or different, representing independently a linearor branched alkyl group having 1 to 6 carbon atoms or representing,together with the nitrogen atom to which they are bound, a 5- to7-membered ring which can comprise at least one other heteroatomselected from oxygen, sulfur and nitrogen, said nitrogen optionallybeing substituted with an R′″ group, a linear or branched alkyl group,having 1 to 6 carbon atoms,

a methacryloyl group or an acryloyl group,

an epoxy group of formula:

in which n=1, 2 or 3,

an aralkyl or heteroaralkyl group, the linear or branched alkyl grouphaving 1 to 4 carbon atoms and the aryl and heteroaryl groups having thedefinitions given above, or

said two substituents R₁ and R₂ together form an adamantyl, a norbornyl,a fluorenylidene, a di(C₁-C₆)alkylanthracenylidene or aspiro(C₅-C₆)cycloalkyl-anthracenylidene group; said group optionallybeing substituted with at least one of the substituents listed above forR₁, R₂: aryl or heteroaryl group;

R₃ and R₄, identical or different, independently represent:

hydrogen,

a halogen, and notably fluorine, chlorine or bromine,

a linear or branched alkyl group having 1 to 12 carbon atoms(advantageously 1 to 6 carbon atoms),

a cycloalkyl group having 3 to 12 carbon atoms,

a linear or branched alkoxy group, having 1 to 12 carbon atoms(advantageously 1 to 6 carbon atoms)

a haloalkyl, a halocycloalkyl or haloalkoxy group correspondingrespectively to the alkyl, cycloalkyl, alkoxy groups above, substitutedwith at least one halogen atom, notably selected from fluorine, chlorineand bromine,

an aryl or heteroaryl group having the same definition as that givenabove for R₁, R₂,

an aralkyl or heteroaralkyl group, the linear or branched alkyl grouphaving 1 to 4 carbon atoms and the aryl and heteroaryl groups having thesame definitions as those given above for R₁, R₂,

an amine or amide group: —NH₂, —NHR, —CONH₂, —CONHR,

 R, R′, R″ having their respective definitions given above for the aminesubstituents of the R₁, R₂ values: aryl or heteroaryl,

an —OCOR₆ or —COOR₆ group, R₆ representing a straight or branched alkylgroup having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6carbon atoms or a phenyl group optionally substituted with at least oneof the substituents listed above for the R₁, R₂ values: aryl orheteroaryl;

m and n are, independently, integers of 0 to 4;

R₅ represents:

hydrogen,

a linear or branched alkyl group having 1 to 12 carbon atoms(advantageously 1 to 6 carbon atoms),

a cycloalkyl group having 3 to 12 carbon atoms,

a linear or branched alkenyl group having 2 to 12 carbon atoms andnotably a vinyl group or an allyl group,

a phenyl or benzyl group, optionally substituted with at least one ofthe substituents listed above for the R₁, R₂ values: aryl or heteroaryl,

a —COR₇, —COOR₇ or CONHR₇ group, R₇ representing a straight or branchedalkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to6 carbon atoms or a linear or branched alkenyl group having 2 to 12carbon atoms and notably an allyl group or a phenyl or benzyl groupoptionally substituted with at least one of the substituents listedabove for the R₁, R₂ values: aryl or heteroaryl,

a methacryloyl group or an acryloyl group,

an epoxy group of formula:

in which n=1, 2 or 3.

Amongst said compounds of formula (I) above, those which are of formula(I1) below are preferred:

in which:

R₁ and/or R₂, identical or different, independently represent optionallysubstituted aryl or heteroaryl groups whose basic structure is selectedfrom those of the phenyl, naphthyl, biphenyl, pyridyl, furyl,benzofuryl, dibenzofuryl, N—(C₁-C₆)alkylcarbazole, thienyl,benzothienyl, dibenzothienyl and julolidinyl groups; R₁ and/or R₂advantageously representing a phenyl group substituted in the paraposition;

R₃ and R₄, identical or different, independently represent hydrogen, alinear or branched alkoxy group having 1 to 6 carbon atoms, a halogen, alinear or branched alkyl group having 1 to 6 carbon atoms, a morpholinogroup or a dialkylamino group—NR′R″ in which R′ and R″ independentlyrepresent a linear or branched alkyl group having 1 to 6 carbon atoms;

R₅ represents hydrogen, a linear or branched alkyl group having 1 to 6carbon atoms, an optionally substituted phenyl or benzyl group, a —COR₇,—COOR₇, or CONHR₇ group, R₇ representing a straight or branched alkylgroup having 1 to 6 carbon atoms or an optionally substituted phenyl orbenzyl group.

Amongst the substituents (R₁, R₂, R₅) of the compounds of the invention,they are some which comprise and/or form at least one polymerizableand/or cross-linkable reactive group. The presence of such reactivegroups can prove to be advantageous. Thus, the present inventionincludes, in its first object, [indole]naphthopyran compounds, such asdefined above, whose structure includes at least one polymerizationand/or cross-linking reactive group; said group consisting of an alkenylgroup, advantageously vinyl or allyl, or of a methacryloyl, acryloyl orepoxy group.

Thus, the compounds of the invention which belong to this class can begrasped as monomers, of different nature or not, which can react withthemselves and/or with other co-monomers in order to form homopolymersand/or copolymers which are carriers of a photochromic functionality(insofar as said monomers of the invention bear said photochromicfunctionality) and possess the mechanical properties of macromolecules.

It follows that another object of the present invention is formed bythese linear or branched homopolymers or copolymers, at least in partconstituted by the compounds of the invention.

Similarly, the above-mentioned compounds of the invention can beenvisaged as cross-linking agents having reactive functions which canallow bridges between chains of photochromic or non-photochromicpolymers. The reticulates (products of cross-linking) which can beobtained also constitute another object of the present invention.

The compounds of the invention—[indole]naphthopyrans of formula (I)—canbe obtained in a general manner by the condensation

of a compound of formula (II) below:

 in which R₃, R₄, m and n are as defined with reference to formula (I)above;

with a propargylic alcohol derivative of formula (III) below:

 in which R₁ and R₂ are as defined with reference to formula (I) above(the condensation reaction can be carried out in solvents such astoluene or tetrahydrofuran in the presence of a catalyst such aspara-toluenesulfonic acid or bromoacetic acid)

or

with, in the presence of titanium tetralkoxide (especially titaniumtetraethoxide), an aldehyde of formula (III′) below

 in which R₁ and R₂ are as defined with reference to formula (I) above(see EP-A-0 562 915 for example).

The compounds of the invention obtained by this condensation and whichare of formula (I_(a)) below (formula (I) in which R₅=H) are thenoptionally, for the preparation of the compounds of formula (I) in whichR₅≠H (formula (I_(b)) below), after deprotonation in the presence ofsodium hydride, reacted with a suitable electrophilic compound offormula R₅X, in which X is a leaving group: which can be schematized bythe reaction below:

Thus, for this synthesis of the [indole]naphthopyrans of the invention,novel compounds of formula (II) are used on the one hand, and compoundsof formula (III) or the corresponding aldehyde derivatives on the other.

Said compounds of formula (III) are known to the person skilled in thatart and are obtained from the corresponding ketone according to a methoddescribed notably in the patent application WO-A-96 14596. The ketone isitself commercial or is prepared according to known methods such as theFriedel Crafts reaction (cf. WO-A-96 14596 and cited references). Thealdehyde derivatives of (III) are obtained by a rearrangement in acidmedium (cf. J. Org. Chem. 1977, 42, 3403).

Said original compounds of formula (II) above open up an original andmagnificent route to the preparation of [indole]naphthopyrans of formula(I) of the invention.

Thus, the other objects of the present invention consist of:

the method of preparing said [indole]naphthopyrans from said compoundsof formula (II) (method specified above);

said compounds of formula (II) themselves; and

the method of preparing said compounds of formula (II); a methoddescribed below.

Said compounds of formula (II) are obtained according to an originalsynthesis scheme whose various steps are known to the person skilled inthe art, or are adapted from the literature. Said synthesis schemecomprises:

submitting the compound of formula (V)

 in which

R₃, R₄, m and n are as defined with reference to formula (I)

and Z represents hydrogen or a labile protecting group such as an acetylgroup;

 to a Curtius rearrangement, in order to obtain the compound of formula(VII):

activating said compound of formula (VII) by diazotation in the presenceof HNO₂, and reacting said activated compound with sodium azide in orderto obtain the corresponding azide of formula (VIII):

photochemically decomposing said azide in order to obtain thecorresponding carbazole, followed if necessary (in the hypothesis whenZ≠H), by the deprotection of the hydroxyl group.

The acids of formula (V) (formula (V_(a)) when Z=H; formula (V_(b)) whenZ≠H), whose hydroxyl function is protected or not by a labile Z group,are easily accessible from the corresponding benzophenones according toa synthesis route described in the application WO-A-96 14596.

Said acids undergo, in a way known per se, a Curtius rearrangement inorder to generate the amines of formula (VII). It is highly recommendedto carry out said Curtius rearrangement under mild conditions accordingto the reaction scheme below:

(with Z≠H; notably Z=acetyl group).

The (V_(a))→(V_(I)) transformation can be deduced from the methoddescribed in J.Am.Chem.Soc.,1972, 94, 6203-6205. The Curtiusrearrangement (V_(b))→(VI) is in general carried out in refluxingtoluene in the presence of diphenylphosphorazide (DPPA), triethylamine(NEt₃) and tert-butanol (tBuOH).

The protected amine function of the compound (VI) is deprotected inorder to lead to the compound (VII), generally with trifluoroacetic acidin dichloromethane.

The aromatic nucleophilic substitution via the diazotation of anarylamine (transformation (VII)→(VIII)) is well known to the personskilled in the art and is described notably in Vogel's Textbook ofPractical Organic Chemistry (fifth edition, p. 922 and seq.).

Finally, the azide (VIII), by photochromic rearrangement, leads to thecarbazole of formula (II). This type of rearrangement of anortho-azidobiphenyl is notably described in The Chemistry ofHeterocycles (Georg Thieme Verlag Stuttgart, New York, 1995), as meansof access to carbazoles.

In the hypothesis wherein Z≠H, the hydroxyl function of the carbazoleobtained must still be deprotected. This deprotection step is carriedout in a manner known per se. Thus, in order to deacylate such afunction, the mild conditions below are advantageously operated under:in tetrahydrofuran with 0.5 N sodium hydroxide at 0° C.

It is to the credit of the Applicant to have prepared and tested theoriginal compounds of formula (I) described above; said compoundspossess particularly advantageous photochromic properties. Morespecifically, these novel compounds possess a high colorability, withhigher λmax values that the known naphthopyrans of analogous structure.

Furthermore, these compounds are compatible with the organic polymer orinorganic material support matrices both in the form included in saidmatrices and in the form of a coating of said matrices.

In solution or in a polymer matrix, the compounds according to theinvention are colorless or faintly colored in the initial sate andrapidly develop an intense coloration under UV light (365 nm) or a lightsource of the solar type. Finally, they regain their initial colorationwhen the irradiation ceases.

According to another of its objects, the present invention relates tothe use of said compounds of formula (I) of the invention asphotochromic agents. In other words, the Applicant presently proposes:

novel photochromic compounds which consist of the naphthopyranderivatives such as defined above ([indole]naphthopyrans), taken aloneor in a mixture of themselves and/or with at least one otherphotochromic compound of another type and/or with at least onenon-photochromic coloring agent;

novel photochromic compositions which comprise at least one naphthopyranderivative ([indole]naphthopyrans) such as defined above and/or at leastone (co)polymer and/or reticulate having at least one of saidnaphthopyran derivatives of the invention in its structure. Suchphotochromic compositions can contain at least one other photochromiccompound, of another type and/or at least one non-photochromic coloringagent and/or at least one stabilizing agent.

Said photochromic compounds of another type, non-photochromic coloringagents, and stabilizing agents are prior art products known to theperson skilled in the art.

Combinations of photochromic compounds of the invention and/orphotochromic compounds of the invention and photochromic compounds ofanother type according to the prior art are particularly recommendedwhich are suitable for generating gray or brown tints.

The compounds of the invention, notably as photochromic compounds, canbe used in solution. Thus, a photochromic solution can be obtained bydissolving at least one of said compounds in an organic solvent such astoluene, dichloromethane, tetrahydrofuran or ethanol. The solutionsobtained are in general colorless and transparent. When exposed tosunlight, they develop a high coloration and regain the colorless statewhen they are placed in an area of less exposure to the sun's rays or,in other words, when they are no longer submitted to UV. In general, avery low concentration of product (of the order of 0.01 to 5% by weight)is sufficient to obtain an intense coloration.

The compounds of the invention ([indole]naphthopyrans of formula (I))can also be used as a photochromic material dispersed uniformly in themass or on the surface of a polymer matrix. In fact, the mostinteresting applications of the compounds of the invention are those inwhich the photochrome is dispersed uniformly within or on the surface ofa polymer, copolymer or mixture of polymers. The (co)polymer matrixwhich comprises said photochrome of the invention (at least one, in afree form, and/or in the form of a (co)polymer and/or reticulate, and/orin the form of a photochromic composition, such as defined above)constitutes another object of the present invention.

The methods of implementation which can be envisaged in order to obtainsuch a matrix are very varied. Amongst those known to the person skilledin the art, the diffusion in the (co)polymer, from a suspension orsolution of the photochrome, in a silicone oil, in an aliphatic oraromatic hydrocarbon, or in a glycol, or from another polymer matrix,can be cited for example. The diffusion is commonly carried out at atemperature of 50 to 200° C. for a period of time of 15 minutes toseveral hours, according to the nature of the polymer matrix. Anotherimplementation technique consists in mixing the photochrome in aformulation of polymerizable matrices, depositing this mixture on asurface or in a mold, and then carrying out the copolymerisation. Theseimplementation techniques, and others, are described in the article byCrano et al. “Spiroxazines and their use in photochromic lenses”published in Applied Photochromic Polymer Systems, Ed. Blackie and SonLtd—1992.

In accordance with a variant of this object of the invention, it is alsoenvisagable to graft the photochromes onto the (co)polymers. Thus, theinvention also relates to the (co)polymers grafted by at least one ofthe photochromes described above. Thus, the expression “(co)polymermatrix comprising at least one photochrome of the invention” means bothmatrices which comprise said photochrome in their mass and on theirsurface, and matrices grafted by said photochrome.

The following products can be mentioned as examples of polymericmaterials preferred for optical applications of the photochromiccompounds according to the invention:

optionally halogenated alkyl, cycloalkyl, aryl or aralkyl poly (mono-,di-, tri- or tetra-) acrylate or poly (mono-, di-, tri- or tetra-)methacrylate or having at least one ether and/or ester and/or carbonateand/or carbamate and/or thiocarbamate and/or urea and/or amide group,

polystyrene, polyether, polyester, polycarbonate (e. g. bisphenol-Apolycarbonate, diallyl diethylene glycol polycarbonate), polycarbamate,polyepoxy, polyurea, polyurethane, polythiourethane, polysiloxane,polyacrylonitrile, polyamide, aliphatic or aromatic polyester, vinylicpolymers, cellulose acetate, cellulose triacetate, celluloseacetate-propionate or polyvinylbutyral,

copolymers of at least two types of co-polymerizable monomers selectedfrom precursor monomers of the polymers listed above (notably selectedfrom (meth)acrylics. vinyls, allyls, and mixtures thereof), and

resins, having a nanobiphasic structure, obtained by copolymerisation ofa mixture of at least one or more difunctional monomers of type (a) andone or more difunctional monomers of type (b):

the difunctional monomer(s) of type (a) being of one or the other offormulae (A) and (A′) hereinafter:

 in which:

R₁, R′₁, R and R′, identical or different, independently are a hydrogenor a methyl group;

m and n are, independently, integers between 0 and 4 inclusive; and areadvantageously independently equal to 1 or 2;

X and X′, identical or different, are a halogen and preferably representchlorine and/or bromine;

p and q are, independently, integers between 0 and 4 inclusive;

 in which:

R₁ and R′₁, identical or different, independently are a hydrogen or amethyl group;

R is a linear or branched alkyl radical having from 2 to 8 carbon atoms,a cycloalkyl radical having from 3 to 6 carbon atoms, an ether radicalof formula (R′—O—R″) in which R′ and R″, identical or different,independently are a linear or branched alkyl radical having from 2 to 4carbon atoms;

the difunctional monomer(s) of type (b)—long chain alkenic difunctionaloligomer—being of one or the other of formulae (B), (B′) and (B″)hereinafter:

 in which:

R₁, R′₁, R₂ and R′₂, identical or different, independently are hydrogenor a linear or branched alkyl radical, advantageously linear, havingfrom 1 to 4 carbon atoms; and correspond particularly advantageously toa methyl group;

R₃ and R₄, different, are independently one hydrogen and the other analkenyl radical having from 2 to 6 carbon atoms, advantageously from 2to 4 carbon atoms and particularly advantageously an isopropenylradical;

R′₃ and R′₄, different, are independently one hydrogen and the other analkenyl radical having from 2 to 6 carbon atoms, advantageously from 2to 4 carbon atoms and particularly advantageously an isopropenylradical;

Z represents a carbamate function (—NH—CO—O—), a thiocarbamate function(—NH—CO—S—) or a urea function (—NH—CO—NH—);

Z′, independent from Z and advantageously respectively with respect toZ, represents a carbamate function (—O—CO—NH—), a thiocarbamate function(—S—CO—NH—) or a urea function (—NH—CO—NH—);

R′ represents a linear or branched alkyl radical having from 2 to 4carbon atoms;

R, identical or different when n≧2, is a linear or branched alkylradical having from 2 to 4 carbon atoms;

Y, identical or different when n≧2, is oxygen or sulfur;

n is an integer defined in such a way that the total number of carbonatoms contained in the long chain situated between the two motifs Z andZ′ be at least equal to 18 and is advantageously between 18 and 112inclusive;

 in which:

R₁, R₂, R₃, R₄, R′₁, R′₂, R′₃, R′₄, R and Y are such as definedhereinabove with reference to formula (B);

n is an integer defined in such a way that the total number of carbonatoms contained in the long chain of the motif (R—Y)_(n) be at leastequal to 22 and is advantageously between 22 and 104 inclusive;

 in which:

R₁, R₂, R₃, R₄, R′₁, R′₂, R′₃, R′₄, R, R′ and Y are such as definedhereinabove with reference to formula (B);

Z′ is a carbamate function (—O—CO—NH—) or Z′ is a thiocarbamate function(—S—CO—NH—);

n is an integer defined in such a way that the total number of carbonatoms contained in the long chain of the motif (R—Y)_(n), be at leastequal to 22 and is advantageously between 22 and 104 inclusive.

Such resins have been described by the Applicant in the French patentApplication FR 97 05458 filed on the May 2, 1997. These resins combinewithin them at least one short-chain difunctional (meth)acrylic monomer(of type (a) above) and at least one long-chain difunctional alkenicmonomer (of type (b) above). Such a combination enables obtaining a verysatisfactory compromise of the photochromic properties/mechanicalproperties.

The [indole]naphthopyrans of formula (I) according to the invention havevery interesting photochromic properties within such resins.

With reference to said resins, it is specified that the intervention:

of tetraethoxylated Bisphenol A dimethacrylate (compound of formula (A)in which R=R′=H, R₁=R′₁=CH₃, m=n=2 and p=q=0) as difunctional monomersof type (a) is most particularly recommended; and the intervention

of long-chain polyoxyalkylene difunctional alkenic oligomers resultingfrom the reaction of at least one alkenylisocyanate (especially3-isopropenyl-α,α-dimethylbenzylisocyanate or m-TMI®) and at least onediamine of formula H₂N—(R—O)_(n)—R′—NH₂, in which R and R′ are asdefined above in reference to the formula (B) (a C₂-C₄ alkyl radical) asdifunctional “monomers” of type (b) is most particularly recommended.

Finally, it is specified in general terms that within said resins, theamount of monomer(s) of type (a) is between 40 and 99 parts by weightfor 100 parts by weight of the mixture of monomers of type (a) and (b).

The amount of photochrome used in the (co)polymer matrix depends uponthe degree of darkening desired. Usually, between 0.001 and 20% byweight of it is used.

The photochromic compounds according to the invention can be used aloneor in a mixture with other products in order to form a composition whichcan be a solid or a liquid, in solution or in suspension for example, ashas already been indicated above. These compositions, which constitutean object of the invention as already indicated above, can thereforecomprise the compounds of the invention and other additionalphotochromic compounds enabling obtaining dark colorations, gray orbrown for example, desired by the public in applications such asophthalmic or solar spectacles trade. These additional photochromiccompounds can be those known to the person skilled in the art anddescribed in the literature, e. g. chromenes (U.S. Pat. Nos. 3,567,605,5,238,981, WO-A-94 22850, EP-A 562 915), spiropyrans ornaphthospiropyrans (U.S. Pat. No. 5,238,981) and spiroxazines (Crano etal., “Applied Photochromic Polymer Systems”, Ed. Blackie & Son Ltd,1992, chapter 2).

Said compositions according to the invention can also comprise:

non-photochromic coloring agents which enable adjusting the tint,

and/or one or more stabilizing agents. such as an anti-oxidizing agentfor example,

and/or one or more anti-UV,

and/or one or more anti-radicals,

and/or one or more photochimic excited state deactivators.

These additives can notably enable improving the durability of saidcompositions.

According to another of its aspects relative to the application of thecompounds of the invention, another object of the present invention isophthalmic articles, such as articles for the ophthalmic and solarspectacles trade, which comprise at least one compound according to theinvention and/or at least one (co)polymer and/or reticulate formed, atleast in part, from compound(s) of the invention and/or at least onecomposition containing at least one compound of the invention and/or atleast one matrix, such as defined above, of an organic polymer materialor an inorganic material or even of an inorganic-organic hybrid materialincorporating therein at least one compound of the invention.

In practice, the articles most particularly covered by the presentinvention are photochromic ophthalmic or solar lenses, glazing (windowpanes for buildings, locomotion engines, automobiles), optical devices,decorative devices, solar protection devices, information storage, . . ..

The present invention is illustrated by the example that follows ofsynthesis and photochromic validation, of a compound of the invention([indole]naphthopyran). Said compound of the invention is compared to aprior art compound C1.

EXAMPLE 1

Synthesis of Compound (1) (R₁=R₂=p-C₆H₄OCH₃, R₃=R₄=H, R₅=CH₃)

Step 1: 10.58 g of acid (of formula V_(a)) (R₃=R₄=H) obtained from thecorresponding benzophenone according to WO-A-96 14596 are added atambient temperature to a suspension of 4 g of NaH (60% in a mineral oil)in 200 ml of THF. After stirring under reflux for 30 min, the mixture iscooled to 0° C. and 3.12 ml of acetyl chloride are added. After stirringfor 1 h 30 at ambient temperature and then under reflux for 30 min, thereaction mixture is hydrolyzed with 100 ml of water, then extracted with200 ml of ethyl acetate. The organic phase is extracted with 2×100 ml of1N sodium hydroxide solution, and the combined aqueous phases areacidified and then extracted with 2×100 ml of ethyl acetate. Afterdrying over magnesium sulfate and evaporation of the solvents, arecrystallization in a mixture of diisopropyl ether/heptane enablesisolating 6.36 g of beige crystals (compound of formula V_(b)).

Step 2: The product obtained from step 1 is placed in suspension in 100ml of toluene, 3.1 ml of triethylamine are then added. Stirring iscarried out for 10 min at ambient temperature, 5.39 ml ofdiphenylphosphorazide are added and stirring is continued for 30 min atambient temperature. 2.36 ml of tert-butanol are added and stirring iscontinued overnight under reflux. After evaporation of the solvent, themixture is taken up into ethyl acetate and is washed with a solution ofsodium bicarbonate. After drying over magnesium sulfate and evaporationof the solvents, the brown oil obtained is crystallized from methanolgiving 5.28 g of a white solid (compound of formula VII protected).

Step 3: The product of step 2 is placed in solution at 0° C. in 90 ml ofa 1/1 mixture of trifluoroacetic acid in dichloromethane. After stirringat 0° C. for 30 min, the reaction mixture is diluted in 150 ml oftoluene and the solvents are evaporated under vacuum. The oil obtainedis taken up into 100 ml of ethyl acetate and then washed with a solutionof sodium bicarbonate. After drying over magnesium sulfate, theevaporation of the solvents allows isolating 4.03 g of a just yellow oil(compound of formula VII deprotected).

Step 4: The product of step 3 is dissolved in 60 ml of acetone and isstirred at 0° C. 10 ml of 12N HCl are added, then 1.105 g of sodiumnitrite (in solution in the minimum of water). Stirring is continued for10 min at 0° C., 1.3 g of solid sodium azide are then cautiously added(Beware of the potential release of hydrazoic acid!). This is stirredfor 15 min at 0° C., diluted in 200 ml of ethyl acetate and is pouredcarefully into a solution of potassium carbonate. The aqueous phaseextracted with 2×50 ml of ethyl acetate and the combined organic phasesare dried over magnesium sulfate and evaporated to dryness. Afterrecrystallization from methanol, 3.74 g of a gray powder are isolated(compound of formula VIII).

Step 5: 1.35 g of the product of step 4 are dissolved in 30 ml of THFand the solution obtained is placed in a quartz recipient. The reactionmixture is irradiated with 2 UV lamps (15 W, 254 and 365 nm, Prolabo,tubes for darkroom CN 15) for 4 days. The solvent is then evaporated.After recrystallization from methanol, 770 mg of a yellow powder areisolated (compound of formula II protected).

Step 6: A solution of 275 mg of product of step 5 in 20 ml of THF iscooled to 0° C. and 10 ml of a cooled 0.5 N NaOH solution are added. Thereaction mixture is stirred for 20 min at 0° C., the reaction is thenquenched with 10 ml of a 1N solution of HCl. This is extracted with 100ml of ethyl acetate, the organic phase is dried over magnesium sulfateand the solvents are evaporated. 225 mg of a just yellow solid are thusobtained (compound of formula II).

Step 7: A catalytic amount (spatula tip) of bromoacetic acid is added toa solution of 150 mg of the product of step 6 and 174 mg ofbis(para-methoxyphenyl)propargylic alcohol in 20 ml of toluene. Afterstirring overnight under reflux, the reaction mixture is purified overneutral alumina (eluent: diisopropyl ether/EtOAc) and the photochrome isrecrystallised from a mixture of diisopropyl ether/heptane giving 130 mgof a green solid (compound of formula I in which R₅=H).

Step 8: A solution of 120 mg of the product of step 7 in 5 ml ofanhydrous THF is cooled to 0° C. 50 mg of NaH (60% in a mineral oil) and0.2 ml of methyl iodide are then added successively. The reactionmixture is stirred for 15 minutes at 0° C. and the reaction is thenquenched with 10 ml of a saturated ammonium chloride solution. This isextracted with 100 ml of EtOAc, dried over MgSO₄ and the solvent isevaporated. After recrystallization from a mixture of diisopropylether/heptane, 65 mg of product (1) are isolated as a green solid(compound of formula I in which R₅=CH₃).

EXAMPLE 2

Compound C1

The prior art compound C1, described in RD 31 144, of formula:

has been considered. This compound is commercially available.

EXAMPLE 3

The photochromic properties of said compounds (1) and C1 were evaluated.

To this end, said compounds are incorporated in a matrix at the rate ofabout 0.05% by weight.

A mixture of the starting materials is in fact carried out, whose natureand intervening amounts are specified below; the mixture is poured intoa lens mold of 2 mm thickness which is then submitted to a hardeningcycle of 2 hours at 75° C. and then 1 hour at 120° C.

The precursor starting materials of the matrix are:

0.05 parts by weight of the photochromic coloring agent: compound (1) orC1; for

11.5 parts by weight of divinylbenzene;

2.9 parts by weight of 2-ethylhexylmethacrylate;

14.4 parts by weight of benzylmethacrylate;

0.5 parts by weight of n-dodecanethiol;

0.2 parts by weight of AMBN (2,2′-azobis(2-methylbutyronitrile) providedby AKZO (Perkadox®));

42.3 parts by weight of DIACRYL 121 from AKZO Chimie (tetraethoxylatedBisphenol A dimethacrylate);

28.8 parts by weight of an isopropenyl oligomer of the type[m-TMI®+poly(oxyethylene)diamine (M=600)+poly(oxyethylene)diamine(M=2000)].

Said isopropenyl oligomer was obtained by reaction of

36.13% by weight of 3-isopropenyl-α,α-dimethylbenzylisocyanate (CYTEC);

44.71% by weight of JEFFAMINE® ED 600 (polyoxypropylene diaminesmarketed by TEXACO);

19.16% by weight of JEFFAMINE® ED 2 000 (polyoxypropylene diaminesmarketed by TEXACO).

Said matrix, containing said photochromic compounds in its mass isexposed to a UV radiation (source: xenon lamp). The λ_(max) values inthe visible and the discoloration kinetics are given in the Table below.

λ₁ λ₂ discoloration λ uv visible visible kinetics DO₁/DO₂ DO₁/DO₂Compound Structure nm nm nm (T_(1/2)) 25° C. 40° C. (1)

402 452 564 36 s 0.84/0.45 0.37/0.20 Cl

365 424 503 92 s 0.59/0.99 0.27/0.46

It is shown by these measurements that the compound of the invention hashigher λ_(max) values than the analogous compound without the indolering ringed in position 5,6 of the naphthopyran. Furthermore, thepresence of the two absorption bands of the compounds of the inventionallow covering a greater range of the visible spectrum. Moreover, afirst band is observed in the visible which is much more intense for thecompounds of the invention, as well as faster discoloration kinetics. Itis also to be noted that the compound (1) of the invention has a UV bandshifted further towards the visible which improves its sensitiveness tosolar light.

What is claimed is:
 1. Compounds of formula (I):

in which: R₁ and R₂, identical or different, independently represent:hydrogen, a linear or branched alkyl group having 1 to 12 carbon atoms,a cycloalkyl group having 3 to 12 carbon atoms, an aryl or heteroarylgroup having 6 to 24 carbon atoms or 4 to 24 carbon atoms respectivelyin its basic structure and at least one heteroatom selected from sulfur,oxygen and nitrogen; said basic structure optionally being substitutedwith at least one substituent selected from: a halogen, a linear orbranched alkyl group having 1 to 12 carbon atoms, a linear or branchedalkoxy group having 1 to 12 carbon atoms, a linear or branched haloalkylor haloalkoxy group corresponding respectively to the (C₁-C₁₂)alkyl and(C₁-C₁₂)alkoxy groups above substituted with at least one halogen atom,a linear or branched alkenyl group having 2 to 12 carbon atoms, an NH₂group, an NHR group, R representing a linear or branched alkyl grouphaving 1 to 6 carbon atoms, a

 R′ and R″, identical or different, representing independently a linearor branched alkyl group having 1 to 6 carbon atoms or representing,together with the nitrogen atom to which they are bound, a 5- to7-membered ring which can comprise at least one other heteroatomselected from oxygen, sulfur and nitrogen, said nitrogen optionallybeing substituted with an R′″ group, wherein the R′″ group is a linearor branched alkyl group having 1 to 6 carbon atoms, an epoxy group offormula:

an aralkyl or heteroaralkyl group, the linear or branched alkyl grouphaving 1 to 4 carbon atoms and the aryl and heteroaryl groups having thedefinitions given above, or said two substituents R₁ and R₂ togetherform an adamantyl, a norbornyl, a fluorenylidene, adi(C₁-C₆)alkylanthracenylidene or aspiro(C₅-C₆)cycloalkylanthracenylidene group; said group optionallybeing substituted with at least one of the substituents listed above forR₁, R₂: aryl or heteroaryl group; R₃ represents: hydrogen, a linear orbranched alkyl group having 1 to 12 carbon atoms, a cycloalkyl grouphaving 3 to 12 carbon atoms, an linear or branched alkoxy group, having1 to 12 carbon atoms, a haloalkyl, a halocycloalkyl or a haloalkoxygroup corresponding respectively to the alkyl, cycloalkyl, or alkoxygroups above, substituted with at least one halogen atom, an aryl orheteroaryl group having the same definition as that given above for R₁,R₂, an aralkyl or heteroaralkyl group, the linear or branched alkylgroup having 1 to 4 carbon atoms and the aryl and heteroaryl groupshaving the same definitions as those given above for R₁, R₂, an —OCOR₆or —COOR₆ group, R₆ representing a straight or branched alkyl grouphaving 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbonatoms or a phenyl group optionally substituted with at least one of thesubstituents listed above for the R₁, R₂ values: aryl or heteroaryl; R₄represents: hydrogen, a halogen, a linear or branched alkyl group having1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, anlinear or branched alkoxy group having 1 to 12 carbon atoms, ahaloalkyl, a halocycloalkyl or a haloalkoxy group correspondingrespectively to the alkyl, cycloalkyl, or alkoxy groups above,substituted with at least one halogen atom, an aryl or heteroaryl grouphaving the same definition as that given above for R₁, R₂, an aralkyl orheteroaralkyl group, the linear or branched alkyl group having 1 to 4carbon atoms and the aryl and heteroaryl groups having the samedefinitions as those given above for R₁, R₂, an amine or amide group:—NH₂, —NHR, —CONH₂, —CONHR,

 R, R′, R″ having their respective definitions given above for the aminesubstituents of the R₁, R₂ values: aryl or heteroaryl, an —OCOR₆ or—COOR₆ group, R₆ representing a straight or branched alkyl group having1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms ora phenyl group optionally substituted with at least one of thesubstituents listed above for the R₁, R₂ values: aryl or heteroaryl; mand n are, independently, integers of 0 to 4; R₅ represents: hydrogen, alinear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkylgroup having 3 to 12 carbon atoms, a linear or branched alkenyl grouphaving 2 to 12 carbon atoms, a phenyl or benzyl group, optionallysubstituted with at least one of the substituents listed above for theR₁, R₂ values: aryl or heteroaryl, a —COR₇, —COOR₇ or —CONHR₇ group, R₇representing a straight or branched alkyl group having 1 to 6 carbonatoms or a cycloalkyl group having 3 to 6 carbon atoms or a linear orbranched alkenyl group having 2 to 12 carbon atoms or a phenyl or benzylgroup optionally substituted with at least one of the substituentslisted above for the R₁, R₂ values: aryl or heteroaryl, a methacryloylgroup or an acryloyl group, an epoxy group of formula:


2. The compounds according to claim 1, of formula (Il):

in which: R₁ and R₂, identical or different, independently representoptionally substituted aryl or heteroaryl groups whose basic structureis selected from those of the phenyl, naphthyl, biphenyl, pyridyl,furyl, benzofuryl, dibenzofuryl, N—(C₁-C₆)alkylcarbazole, thienyl,benzothienyl, dibenzothienyl and julolidinyl groups; R₃ representshydrogen, a linear or branched alkoxy group having 1 to 6 carbon atoms,a linear or branched alkyl group having 1 to 6 carbon atoms; R₄represents hydrogen, a linear or branched alkoxy group having 1 to 6carbon atoms, a halogen, a linear or branched alkyl group having 1 to 6carbon atoms, a morpholino group or a dialkylamino group —NR′R″ in whichR′ and R″ independently represent a linear or branched alkyl grouphaving 1 to 6 carbon atoms; and R₅ represents hydrogen, a linear orbranched alkyl group having 1 to 6 carbon atoms, an optionallysubstituted phenyl or benzyl group, a —COR₇, —COOR₇, or —CONHR₇ group,R₇ representing a straight or branched alkyl group having 1 to 6 carbonatoms or an optionally substituted phenyl or benzyl group.
 3. A methodof preparing compounds of formula (I) according to claim 1,characterised in that it comprises: condensing a compound of formula(II):

 in which R₃, R₄, m and n are as defined in claim 1, with reference toformula (I); either with a propargylic alcohol derivative of formula(III) below:

 in which R₁ and R₂ are as defined in claim 1 with reference to formula(I); or with, in the presence of titanium tetralkoxide, an aldehyde offormula (III′) below

 in which R₁ and R₂ are as defined in claim 1 with reference to formula(I); in order to obtain compounds of formula (I) in which R₅ representshydrogen; deprotonating, in the presence of sodium hydride, saidcompounds of formula (I) in which R₅ represents hydrogen and reactingthem with an electrophilic compound of formula R₅X, in which R₅ is asdefined in claim 1 but different from hydrogen and X is a leaving group,in order to obtain compounds of formula (I) in which R₅ is differentfrom hydrogen.
 4. A photochromic compound comprising a compoundaccording to claim 1, or of a mixture of at least two compoundsaccording to claim 1, or of a mixture of at least one compound accordingto claim 1 with at least one other photochromic compound of another typeand/or at least one non-photochromic coloring agent.
 5. A photochromiccomposition comprising: at least one compound according to claim 1, andoptionally, at least one other photochromic compound of another typeand/or at least one non-photochromic coloring agent and/or at least onestabilizing agent.
 6. An ophthalmic or solar article comprising: atleast one compound according to claim
 1. 7. The article according toclaim 6, wherein the article is constituted by a lens.
 8. A glazingand/or optical device comprising: at least one compound according toclaim
 1. 9. An ophthalmic or solar article comprising: at least onecomposition according to claim
 5. 10. The article according to claim 9,wherein the article is constituted by a lens.
 11. A glazing and/oroptical device comprising: at least one composition according to claim5.